Abstract

The effects of Δ9-tetrahydrocannabinol (THC) on neural activity in the rat were investigated using [14C]2-deoxyglucose autoradiography to measure local cerebral glucose use. Overall, THC reduced glucose use at 5 mg/kg and slightly increased it at 1 mg/kg. Significant reductions were seen at the higher dose in regions of the hippocampus and limbic system, and in structures associated with sensory and sensorimotor process ing, consistent with the effects of THC on memory, sensory perception and motor control. Glucose use was increased in the shell of the nucleus accumbens at 1 mg/kg but not reduced at 5 mg/kg. This may reflect increases in activity in mesolimbic reward pathways which at the higher dose are mitigated by reduced glutamatergic outflow from the hippocampus.